New Conjugates of Hyaluronic Acid with γ-Cyclodextrin as Sorafenib Carrier in Cancer Cells.

: In recent years, nanoparticles based on cyclodextrins have been widely investigated, mainly for drug delivery. In this work, we synthesized nanoparticles with a hyaluronic acid backbone (11 kDa and 45 kDa) functionalized with γ-cyclodextrins. We tested sorafenib in the presence of the new hyaluronan-cyclodextrin conjugates in A2780 (ovarian cancer), SK-HeP-1 (adenocarcinoma) and MDA-MB-453 (breast cancer) cell lines. We found that hyaluronan-cyclodextrin conjugates improve the antiproliferative activity of sorafenib. Remarkably, the system based on the 11 kDa hyaluronan conjugate was the most effective and, in the MDA-MB-453 cell line, significantly reduced the IC50 value of sorafenib cells by about 75%.

Aß8-20 Fragment as an Anti-Fibrillogenic and Neuroprotective Agent: Advancing toward Efficient Alzheimer's Disease Treatment.

Alzheimer's disease (AD) is the most common cause of dementia, characterized by a spectrum of symptoms associated with memory loss and cognitive decline with deleterious consequences in everyday life. The lack of specific drugs for the treatment and/or prevention of this pathology makes AD an ever-increasing economic and social emergency. Oligomeric species of amyloid-beta (Aß) are recognized as the primary cause responsible for synaptic dysfunction and neuronal degeneration, playing a crucial role in the onset of the pathology. Several studies have been focusing on the use of small molecules and peptides targeting oligomeric species to prevent Aß aggregation and toxicity. Among them, peptide fragments derived from the primary sequence of Aß have also been used to exploit any eventual recognition abilities toward the full-length Aß parent peptide. Here, we test the Aß8-20 fragment which contains the self-recognizing Lys-Leu-Val-Phe-Phe sequence and lacks Arg 5 and Asp 7 and the main part of the C-terminus, key points involved in the aggregation pathway and stabilization of the fibrillary structure of Aß. In particular, by combining chemical and biological techniques, we show that Aß8-20 does not undergo random coil to ß sheet conformational transition, does not form amyloid fibrils by itself, and is not toxic for neuronal cells. Moreover, we demonstrate that Aß8-20 mainly interacts with the 4-11 region of Aß1-42 and inhibits the formation of toxic oligomeric species and Aß fibrils. Finally, our data show that Aß8-20 protects neuron-like cells from Aß1-42 oligomer toxicity. We propose Aß8-20 as a promising drug candidate for the treatment of AD.

Pairwise and high-order dependencies in the cryptocurrency trading network.

In this paper we analyse the effects of information flows in cryptocurrency markets. We first define a cryptocurrency trading network, i.e. the network made using cryptocurrencies as nodes and the Granger causality among their weekly log returns as links, later we analyse its evolution over time. In particular, with reference to years 2020 and 2021, we study the logarithmic US dollar price returns of the cryptocurrency trading network using both pairwise and high-order statistical dependencies, quantified by Granger causality and O-information, respectively. With reference to the former, we find that it shows peaks in correspondence of important events, like e.g., Covid-19 pandemic turbulence or occasional sudden prices rise. The corresponding network structure is rather stable, across weekly time windows in the period considered and the coins are the most influential nodes in the network. In the pairwise description of the network, stable coins seem to play a marginal role whereas, turning high-order dependencies, they appear in the highest number of synergistic information circuits, thus proving that they play a major role for high order effects. With reference to redundancy and synergy with the time evolution of the total transactions in US dollars, we find that their large volume in the first semester of 2021 seems to have triggered a transition in the cryptocurrency network toward a more complex dynamical landscape. Our results show that pairwise and high-order descriptions of complex financial systems provide complementary information for cryptocurrency analysis.

Quantifying the relationship between specialisation and reputation in an online platform.

Online platforms implement digital reputation systems in order to steer individual user behaviour towards outcomes that are deemed desirable on a collective level. At the same time, most online platforms are highly decentralised environments, leaving their users plenty of room to pursue different strategies and diversify behaviour. We provide a statistical characterisation of the user behaviour emerging from the interplay of such competing forces in Stack Overflow, a long-standing knowledge sharing platform. Over the 11 years covered by our analysis, we represent the interactions between users and topics as bipartite networks. We find such networks to display nested structures akin to those observed in ecological systems, demonstrating that the platform's user base consistently self-organises into specialists and generalists, i.e., users who focus on narrow and broad sets of topics, respectively. We relate the emergence of these behaviours to the platform's reputation system with a series of data-driven models, and find specialisation to be statistically associated with a higher ability to post the best answers to a question. We contrast our findings with observations made in top-down environments-such as firms and corporations-where generalist skills are consistently found to be more successful.

Aß and Tau Interact with Metal Ions, Lipid Membranes and Peptide-Based Amyloid Inhibitors: Are These Common Features Relevant in Alzheimer's Disease?

In the last two decades, the amyloid hypothesis, i.e., the abnormal accumulation of toxic Aß assemblies in the brain, has been considered the mainstream concept sustaining research in Alzheimer's Disease (AD). However, the course of cognitive decline and AD development better correlates with tau accumulation rather than amyloid peptide deposition. Moreover, all clinical trials of amyloid-targeting drug candidates have been unsuccessful, implicitly suggesting that the amyloid hypothesis needs significant amendments. Accumulating evidence supports the existence of a series of potentially dangerous relationships between Aß oligomeric species and tau protein in AD. However, the molecular determinants underlying pathogenic Aß/tau cross interactions are not fully understood. Here, we discuss the common features of Aß and tau molecules, with special emphasis on: (i) the critical role played by metal dyshomeostasis in promoting both Aß and tau aggregation and oxidative stress, in AD; (ii) the effects of lipid membranes on Aß and tau (co)-aggregation at the membrane interface; (iii) the potential of small peptide-based inhibitors of Aß and tau misfolding as therapeutic tools in AD. Although the molecular mechanism underlying the direct Aß/tau interaction remains largely unknown, the arguments discussed in this review may help reinforcing the current view of a synergistic Aß/tau molecular crosstalk in AD and stimulate further research to mechanism elucidation and next-generation AD therapeutics.

KLVFF oligopeptide-decorated amphiphilic cyclodextrin nanomagnets for selective amyloid beta recognition and fishing.

Recognition and capture of amyloid beta (Aß) is a challenging task for the early diagnosis of neurodegenerative disorders, such as Alzheimer's disease. Here, we report a novel KLVFF-modified nanomagnet based on magnetic nanoparticles (MNP) covered with a non-ionic amphiphilic ß-cyclodextrin (SC16OH) and decorated with KLVFF oligopeptide for the self-recognition of the homologous amino-acids sequence of Aß to collect Aß (1-42) peptide from aqueous samples. MNP@SC16OH and MNP@SC16OH/Ada-Pep nanoassemblies were fully characterized by complementary techniques both as solid powders and in aqueous dispersions. Single domain MNP@SC16OH/Ada-Pep nanomagnets of 20-40 nm were observed by TEM analysis. DLS and ζ-potential measurements revealed that MNP@SC16OH nanoassemblies owned in aqueous dispersion a hydrodynamic radius of about 150 nm, which was unaffected by Ada-Pep decoration, while the negative ζ-potential of MNP@SC16OH (-40 mV) became less negative (-30 mV) in MNP@SC16OH/Ada-Pep, confirming the exposition of positively charged KLVFF on nanomagnets surface. The ability of MNP@SC16OH/Ada-Pep to recruit Aß (1-42) in aqueous solution was evaluated by MALDI-TOF and compared with the ineffectiveness of undecorated MNP@SC16OH and VFLKF scrambled peptide-decorated nanoassemblies (MNP@SC16OH/Ada-scPep), pointing out the selectivity of KLVFF-decorated nanohybrid towards Aß (1-42). Finally, the property of nanomagnets to extract Aß in conditioned medium of cells over-producing Aß peptides was investigated as proof of concept of effectiveness of these nanomaterials as potential diagnostic tools.

Cyclodextrin Polymers as Delivery Systems for Targeted Anti-Cancer Chemotherapy.

In the few last years, nanosystems have emerged as a potential therapeutic approach to improve the efficacy and selectivity of many drugs. Cyclodextrins (CyDs) and their nanoparticles have been widely investigated as drug delivery systems. The covalent functionalization of CyD polymer nanoparticles with targeting molecules can improve the therapeutic potential of this family of nanosystems. In this study, we investigated cross-linked γ- and ß-cyclodextrin polymers as carriers for doxorubicin (ox) and oxaliplatin (Oxa). We also functionalized γ-CyD polymer bearing COOH functionalities with arginine-glycine-aspartic or arginine moieties for targeting the integrin receptors of cancer cells. We tested the Dox and Oxa anti-proliferative activity in the presence of the precursor polymer with COOH functionalities and its derivatives in A549 (lung, carcinoma) and HepG2 (liver, carcinoma) cell lines. We found that CyD polymers can significantly improve the antiproliferative activity of Dox in HepG2 cell lines only, whereas the cytotoxic activity of Oxa resulted as enhanced in both cell lines. The peptide or amino acid functionalized CyD polymers, loaded with Dox, did not show any additional effect compared to the precursor polymer. Finally, studies of Dox uptake showed that the higher antiproliferative activity of complexes correlates with the higher accumulation of Dox inside the cells. The results show that CyD polymers could be used as carriers for repositioning classical anticancer drugs such as Dox or Oxa to increase their antitumor activity.

Novel Peptide-Calix[4]arene Conjugate Inhibits Aß Aggregation and Rescues Neurons from Aß's Oligomers Cytotoxicity In Vitro.

Alzheimer's disease (AD) is a progressive neurodegenerative condition affecting people in the elderly. Targeting aggregation of ß-amyloid peptides (Aß) is considered a promising approach for the therapeutic treatment of the disease. Peptide based inhibitors of ß-amyloid fibrillation are emerging as safe drug candidates as well as interesting compounds for early diagnosis of AD. Peptide conjugation via covalent bond with functional moieties enables the resultant hybrid system to acquire desired functions. Here we report the synthesis, the structural characterization, and the Aß42 interaction of a p-amino-calix[4]arene derivative bearing a GPGKLVFF peptide pendant at the lower rim. We demonstrate that the p-amino-calix[4]arene-GPGKLVFF conjugate alters the Aß42 aggregation pathways by preventing Aß42's conformational transition from random coil to ß-sheet with concomitant changes of the aggregation kinetic profile as evidenced by circular dichroism (CD), thioflavin T (ThT), and dynamic light scattering (DLS) measurements, respectively. High resolution mass spectrometry (HR-MS) confirmed a direct interaction of the p-amino-calix[4]arene-GPGKLVFF conjugate with Aß42 monomer which provided insight into a possible working mechanism, whereas the alteration of the Aß42's fibrillary architecture, by the calix-peptide conjugate, was further validated by atomic force microscopy (AFM) imaging. Finally, the herein proposed compound was shown to be effective against Aß42 oligomers' toxicity in differentiated neuroblastoma cells, SH-SY5Y.

Tau/Aß chimera peptides: A Thioflavin-T and MALDI-TOF study of Aß amyloidosis in the presence of Cu(II) or Zn(II) ions and total lipid brain extract (TLBE) vesicles.

Currently, Alzheimer's Disease (AD) is a complex neurodegenerative condition, with limited therapeutic options. Several factors, like Amyloid ß (Aß) aggregation, tau protein hyperphosphorylation, bio-metals dyshomeostasis and oxidative stress contribute to AD pathogenesis. These pathogenic processes might occur in the aqueous phase but also on neuronal membranes. Thus, investigating the connection between Aß and biomembranes, becomes important for unveiling the molecular mechanism underlying Aß amyloidosis as a critical event in AD pathology. In this work, the interaction of two peptides, made up with hybrid sequences from Tau protein 9-16 (EVMEDHAG) or 26-33 (QGGYTMHQ) N-terminal domain and Aß16-20 (KLVFF) hydrophobic region, with full length Aß40 or Aß42 peptides is reported. The studied "chimera" peptides Ac-EVMEDHAGKLVFF-NH2 (τ9-16-KL) and Ac-QGGYTMHQKLVFF-NH2 (τ26-33-KL) are endowed with Aß recognition and metal ion interaction capabilities provided by the tau or Aß sequences, respectively. These peptides were characterized in previous study along with their metal dependent interaction and amyloidogenesis, either in the presence or absence of metal ion and artificial membranes made up with Total Lipid Brain Extract (TLBE) components, (Sciacca et al., 2020). In the present paper, the ability of the two peptides to inhibit Aß aggregation is studied using composite experimental conditions including aqueous solution, the presence of metal ions (Cu or Zn), the presence of lipid vesicles mimicking neuronal membranes as well as the co-presence of metals and TLBE artificial membranes. We used Thioflavine-T (ThT) fluorescence or MALDI-TOF spectrometry analysis of Aß limited proteolysis to respectively monitor the Aß aggregation kinetic or validation of the Aß interacting regions. We demonstrate that τ9-16-KL and τ26-33-KL peptides differently affect Aß aggregation kinetics, with the tau sequence playing a crucial role. The results are discussed in terms of chimera's peptides hydrophobicity and electrostatic driven interactions at the aqueous/membrane interface.

Copper (II) binding properties of an octapeptide fragment from the R3 region of tau protein: A combined potentiometric, spectroscopic and mass spectrometric study.

The copper(II) complexes of a peptide fragment of the R3 domain of tau protein (tau(326-333) Ac-GNIHHKPG-NH2) and its mutants (Ac-GNGHHKPG-NH2, Ac-GNIHHKAG-NH2, Ac-GNGAHKPG-NH2 and Ac-GNGHAKPG-NH2) have been studied by potentiometric and spectroscopic (UV-Vis, CD) methods. ESR spectroscopy and mass spectrometry were also used to prove the coordination mode of the mononuclear complexes and the formation of dinuclear species, respectively. It has been demonstrated that the (326-333) fragment of tau protein is a versatile and effective ligand for copper(II) coordination. The versatility of copper(II) binding is related to the presence of two adjacent histidyl residues in the sequence, which results in the coexistence of mononuclear, bis(ligand) and dinuclear complexes at different metal to ligand ratios. The 1:1 mononuclear complexes are, however, the dominant species with all peptides and the imidazole-N and one to three deprotonated amide nitrogen atoms towards the N-terminal side of the histidyl residue have been suggested as metal binding sites. This binding mode allows the formation of coordination isomers because any of the two histidine moieties can be the primary anchoring site. It is evident from the CD spectroscopic measurements that the isomers are present in almost equal concentration. The copper(II) binding affinity of the native fragment of tau protein is comparable to that of a similar 2-histidine fragment of amyloid-ß mutant, Ac-SGAEGHHQK-NH2 but the comparison with an independent histidyl residue (H32) from the N-terminal region of the protein reveals the predominance of H32 over the histidines in the R3 domain.

Comparison of Centella with Flavonoids for Treatment of Symptoms in Hemorrhoidal Disease and After Surgical Intervention: A Randomized Clinical Trial.

Phlebotonics' effects were evaluated to reduce time-to-stop bleeding and anal irritation in 130 patients who complained of hemorrhoidal disease (HD); bleeding and pain after hemorrhoidectomy (31 patients) and hemorrhoidal thrombosis (34 patients) in the short time. Sixty patients were randomized to receive the routine treatment (both conservative and surgical) (control Group C). The treated group (both conservative and surgical) was divided into two subgroups: one treated with flavonoids (Group A, n = 73), the other with Centella (Group B, n = 66). Time-to-stop bleeding was checked at baseline and checkups (0 up to day 42). Healing was estimated with Kaplan-Meier method, the Kruskal-Wallis test estimated changes in the VAS scores. The HD median time-to-stop bleeding was 2 weeks for Groups A and B; 3 weeks for Group C. VAS scores comparison among Groups (irritation): A vs C, p = 0.007; B vs C, p = 0.041; and A vs B, p = 0.782 resulted respectively. As for operated hemorrhoids, the time-to-stop bleeding was 3 and 4 weeks in Groups A and B and 5 in Group C. Histopathology showed an association between flavonoids and piles' fibrosis (p = 0.008). Phlebotonics in HD, as well as after surgery, showed significant beneficial effects. Flavonoids are the most effective phlebotonics against bleeding and anal irritation.

Tau/Aß chimera peptides: Evaluating the dual function of metal coordination and membrane interaction in one sequence.

Several abnormal events may concur as major risk factors for Alzheimer's disease (AD) pathogenesis. For instance, dysregulation of brain's metal homeostasis and amyloid-mediated membrane damage are established toxic mechanisms causing neuronal death. In this study, we assess the amyloidogenic propensity and membrane-damage effects, either in the presence or in absence of metal ions, of two newly synthesized bifunctional peptides. These were designed to comprise a metal chelating N-terminus region derived from Tau protein namely the Tau9-16 (EVMEDHAG) or Tau26-33 (QGGYTMHQ) sequences, merged with the C-terminal hydrophobic region analogous to the Amyloid beta (Aß) 16-20 aminoacid sequence KLVFF (KL). Comparative circular dichroism or fluorescence experiments were carried out to look at the peptide conformation, fibril formation and membrane affinity of Tau9-16KL and Tau26-33KL peptides. We found that Tau9-16KL and Tau26-33KL perturb the fibrillogenic process of Aß1-40. Furthermore Cu(II) and, to a lower extent, Zn(II) induced conformational changes Tau26-33KL both in water and in membrane-mimicking environment. By contrast, due to a different metal coordination mode we observed for Tau9-16KL an unstructured peptide conformation in all the experimental conditions. Unlike aqueous solution, a certain propensity to form amyloid structures at the lipid membrane interface clearly emerged for both the peptides. However, the two peptides exhibit a different capability to elicit membrane damage depending on the presence or absence of metal ions. Tau9-16KL and Tau26-33KL can be used as peptide-based molecular systems able to interfere with the metal dependent Aß/Tau cross-seeded generation of membrane active amyloid species.

Ion mobility spectrometry combined with multivariate statistical analysis: revealing the effects of a drug candidate for Alzheimer's disease on Aß1-40 peptide early assembly.

Inhibition of the initial stages of amyloid-ß peptide self-assembly is a key approach in drug development for Alzheimer's disease, in which soluble and highly neurotoxic low molecular weight oligomers are produced and aggregate in the brain over time. Here we report a high-throughput method based on ion mobility mass spectrometry and multivariate statistical analysis to rapidly select statistically significant early-stage species of amyloid-ß1-40 whose formation is inhibited by a candidate theranostic agent. Using this method, we have confirmed the inhibition of a Zn-porphyrin-peptide conjugate in the early self-assembly of Aß40 peptide. The MS/MS fragmentation patterns of the species detected in the samples containing the Zn-porphyrin-peptide conjugate suggested a porphyrin-catalyzed oxidation at Met-35(O) of Aß40. We introduce ion mobility MS combined with multivariate statistics as a systematic approach to perform data analytics in drug discovery/amyloid research that aims at the evaluation of the inhibitory effect on the Aß early assembly in vitro models at very low concentration levels of Aß peptides.

Preclinical evidence of enhanced analgesic activity of duloxetine complexed with succinyl-ß-cyclodextrin: A comparative study with cyclodextrin complexes.

Chronic pain represents one of the most important public health problems, with a great prevalence of comorbidity with depression and cognitive decline. Antidepressants such as duloxetine, a serotonin-norepinephrine reuptake inhibitor, represent an essential part of the therapeutic strategy for chronic pain management in addition to classical analgesics. Duloxetine is endowed with good efficacy and a good profile of safety and tolerability. Yet, duloxetine is metabolized by the cytochrome P450 system 2D6 and 1A2 (CYP2D6 and CYP1A2) and it exhibits moderate inhibitory activity on CYP2D6, resulting in side effects and metabolic interactions that may occur on a long term therapeutic schedule. Cyclodextrins (CyDs) are used in pharmaceutical applications for numerous purposes, including the improvement of drug bioavailability. In order to evaluate their effects on the activity of duloxetine, we first spectrophotometrically studied the host-guest complexes obtained combining duloxetine and different ß-CyD derivatives (ß-CyD, ß-CyDen-c-(Glu-Glu), and succinyl-ß-CyD) and then performed in vivo and in vitro studies. Among duloxetine/CyDs complexes, succinyl-ß-CyD ameliorated the analgesic activity of duloxetine in the tail flick test and in the formalin test in mice and significantly protected the drug from CYP2D6 metabolism.

The ability of the NiSOD binding loop to chelate zinc(ii): the role of the terminal amino group in the enzymatic functions.

Equilibrium and detailed spectroscopic characterization of zinc(ii) complexes with NiSOD binding loop and their related model fragments are reported in the whole investigated pH-range. The zinc(ii) complexes of L1 (HCDLPCGVY-NH2), L2 (Ac-HCDLPCGVY-NH2) and L3 (HCDLACGVY-NH2) and the nickel(ii) and zinc(ii) complexes of L4 (HCDLPCG-NH2) were studied by pH-potentiometric and several spectroscopic methods. The results indicated that the macrochelate coordinated zinc(ii) complexes are dominant in a whole pH-range and the side chain donors of the peptides are involved in the metal binding. Therefore, the deprotonation and coordination of the peptide backbone occur only in a strongly alkaline solution. The acetylation of the peptide amino terminus (L2) significantly enhances the zinc(ii) binding ability compared to the corresponding nickel(ii) complexes. L2 complexes of zinc(ii) are 2 or 3 orders of magnitude more stable than the corresponding nickel(ii) complexes. This effect clearly shows the crucial role of the terminal amino group in the nickel binding for the NiSOD enzyme.

Copper(II) Coordination Abilities of the Tau Protein's N-Terminus Peptide Fragments: A Combined Potentiometric, Spectroscopic and Mass Spectrometric Study.

Copper(II) complexes of the N-terminal peptide fragments of tau protein have been studied by potentiometric and various spectroscopic techniques (UV-vis, CD, ESR and ESI-MS). The octapeptide Tau(9-16) (Ac-EVMEDHAG-NH2 ) contains the H14 residue of the native protein, while Tau(26-33) (Ac-QGGYTMHQ-NH2 ) and its mutants Tau(Q26K-Q33K) (Ac-KGGYTMHK-NH2 ) and Tau(Q26K-Y29A-Q33K) (Ac-KGGATMHK-NH2 ) include the H32 residue. To compare the binding ability of H14 and H32 in a single molecule the decapeptide Ac-EDHAGTMHQD-NH2 (Tau(12-16)(30-34)) has also been synthesized and studied. The histidyl residue is the primary metal binding site for metal ions in all the peptide models studied. In the case of Tau(9-16) the side chain carboxylate functions enhance the stability of the M-Nim coordinated complexes compared to Tau(26-33) (logK(Cu-Nim )=5.04 and 3.78, respectively). Deprotonation and metal ion coordination of amide groups occur around the physiological pH range for copper(II). The formation of the imidazole- and amide-coordinated species changes the metal ion preference and the complexes formed with the peptides containing the H32 residue predominate over those of H14 at physiological pH values (90 %-10 %) and in alkaline samples (96 %-4 %).

Cyclodextrin polymers decorated with RGD peptide as delivery systems for targeted anti-cancer chemotherapy.

Polymeric cyclodextrin-based nanoparticles are currently undergoing clinical trials as nanotherapeutics. Using a non-covalent approach, we decorated two cross-linked cyclodextrin polymers of different molecular weights with an RGD peptide derivative to construct a novel carrier for the targeted delivery of doxorubicin. RGD is the binding sequence for the integrin receptor family that is highly expressed in tumour tissues. The assembled host-guest systems were investigated using NMR and DLS techniques. We found that, in comparison with free doxorubicin or the binary complex doxorubicin/cyclodextrin polymer, the RGD units decorating the cyclodextrin-based nanosystems improved the selectivity and cytotoxicity of the complexed doxorubicin towards cultured human tumour cell lines. Our results suggest that the nanocarriers under study may contribute to the development of new platforms for cancer therapy.

Comparison of Flavonoids and Centella asiatica for the treatment of chronic anal fissure. A randomized clinical trial.

AIMS: We aim to test and compare the effects of Flavonoids (Fs) and Centella asiatica (Ca), and the traditional treatment to find out which best deals with healing time, bleeding and pain in the treatment of chronic Anal Fissure (AF). Materials of Study: 98 outpatients were divided randomly into treated (either Fs or Ca) and control group. The control group (Group C, n=32) received the traditional treatment along with the other two subgroups which were treated, additionally, with Fs (Group A, n=30) or Ca (Group B, n=36). Patients were observed once weekly over 8 consecutive weeks. RESULTS: The median time to stop bleeding in the group A was 1 week, in the Group B was 3 weeks and in the group C was 4 weeks. There were significant differences between Groups in terms of time to end bleeding (A vs B: p-value= 0.022; A vs C: p-value<0.001; B vs C: p-value=0.070). As for pain score from baseline to the 2nd week were statistically different between Groups A and B on the one hand and Group C on the other hand (A vs C: p-value=0.004; B vs C: p-value 0.035). All patients healed within 8th week. DISCUSSION: Either patients treated with Fs or Ca experienced early pain disappearance. Fs and Ca did not show side effects CONCLUSIONS: The treatment with Fs is the most effective for bleeding. Patients additionally treated with either Fs or Ca experienced an earlier healing and disappearance of pain in comparison with patients underwent to the traditional treatment. KEY WORDS: Anal bleeding, Anal fissure, Defecation pain.

Repurposing of Copper(II)-chelating Drugs for the Treatment of Neurodegenerative Diseases.

BACKGROUND: There is mounting urgency to find new drugs for the treatment of neurodegenerative disorders. A large number of reviews have exhaustively described either the molecular or clinical aspects of neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's (PD). Conversely, reports outlining how known drugs in use for other diseases can also be effective as therapeutic agents in neurodegenerative diseases are less reported. This review focuses on the current uses of some copper(II) chelating molecules as potential drug candidates in neurodegeneration. METHODS: Starting from the well-known harmful relationships existing between the dyshomeostasis and mis-management of metals and AD onset, we surveyed the experimental work reported in the literature, which deals with the repositioning of metal-chelating drugs in the field of neurodegenerative diseases. The reviewed papers were retrieved from common literature and their selection was limited to those describing the biomolecular aspects associated with neuroprotection. In particular, we emphasized the copper(II) coordination abilities of the selected drugs. RESULTS: Copper, together with zinc and iron, are known to play a key role in regulating neuronal functions. Changes in copper homeostasis are crucial for several neurodegenerative disorders. The studies included in this review may provide an overview on the current strategies aimed at repurposing copper (II) chelating drugs for the treatment of neurodegenerative disorders. Starting from the exemplary case of clioquinol repurposing, we discuss the challenge and the opportunities that repurposing of other metal-chelating drugs may provide (e.g. PBT-2, metformin and cyclodipeptides) in the treatment of neurodegenerative disease. CONCLUSIONS: In order to improve the success rate of drug repositioning, comprehensive studies on the molecular mechanism and therapeutic efficacy are still required. The present review upholds that drug repurposing makes significant advantages over drug discovery since repositioned drugs had already passed the safety and toxicity tests. Promising drug candidates in neurodegenerative diseases may be represented by copper chelating classes of drugs, provided that sufficient details on their mechanism of action are available to encourage further investigations and clinical trials.

Extracellular truncated tau causes early presynaptic dysfunction associated with Alzheimer's disease and other tauopathies.

The largest part of tau secreted from AD nerve terminals and released in cerebral spinal fluid (CSF) is C-terminally truncated, soluble and unaggregated supporting potential extracellular role(s) of NH2 -derived fragments of protein on synaptic dysfunction underlying neurodegenerative tauopathies, including Alzheimer's disease (AD). Here we show that sub-toxic doses of extracellular-applied human NH2 tau 26-44 (aka NH 2 htau) -which is the minimal active moiety of neurotoxic 20-22kDa peptide accumulating in vivo at AD synapses and secreted into parenchyma- acutely provokes presynaptic deficit in K+ -evoked glutamate release on hippocampal synaptosomes along with alteration in local Ca2+ dynamics. Neuritic dystrophy, microtubules breakdown, deregulation in presynaptic proteins and loss of mitochondria located at nerve endings are detected in hippocampal cultures only after prolonged exposure to NH 2 htau. The specificity of these biological effects is supported by the lack of any significant change, either on neuronal activity or on cellular integrity, shown by administration of its reverse sequence counterpart which behaves as an inactive control, likely due to a poor conformational flexibility which makes it unable to dynamically perturb biomembrane-like environments. Our results demonstrate that one of the AD-relevant, soluble and secreted N-terminally truncated tau forms can early contribute to pathology outside of neurons causing alterations in synaptic activity at presynaptic level, independently of overt neurodegeneration.